Aerosol technology AEROPAC

In the traditional technology of compressed gas filling into an aerosol can, the working gas quantity depends on its solubility in spraying substance, volume of the can headspace and the initial charge pressure level. The application of a compressed gas in this way results in an undesirable effects both for manufacturers and product end users, because even at dangerously high initial pressure less than 60 % of the can volume can be filled to secure necessary spray pattern during the life of the can.

Moreover, due to a relatively low solubility of gases in water (3 times lower than in alcohol), aerosol producers are forced to forego cheap and environmentally friendly water-based formulations in favor of flammable alcohol-based formulations with all their side effects including harmful VOC emissions.

Compressed gas aerosol cans still didn’t «take off» in spite of recent efforts/inventions improving their performance.

For example, the use of CO₂ in aerosols has come about mainly due to necessity. Carbon dioxide is technically better propellant in that it retains its pressure at low temperatures what is important particularly in deicers.  Today,  carbon  dioxide (the same gas which puts the «fizz» in soda pop) is used in products designed to deliver a coarse spray at close range; in household desinfectants, for example.  Nitrogen, as used in contact lens cleaners, and nitrous oxide, as used in whipped toppings, are also used as propellants.

Although alternative propelling methods or propellants have been developed and marketed, most of them are either too expensive, complicated, delicate, unsafe or don’t secure constant pressure and spray pattern.

The primary propellants used in today's aerosols are propane and butane, hydrocarbons that contribute  to global warming. The carbon dioxide used in some aerosols is taken from the atmosphere, and therefore presents a net zero global warming impact.

The key to opening a new marketing opportunities in aerosol products based on combination of water + neutral safe propellant such as CO2 or N2 + plastic (PET) attractive package is the use of additional gas source in simple form of sorbed storage in separate capsule.

At moderate pressures (less than 9-10 bar) the storage capacity of modern cheap sorbent is as high as 0.4 – 0.5g of gas per gram of sorbent. It means that in 50 ml capsule the volume of sorbed gas is about 5,000 ml.

The AEROPAC capsule as a source of stored gas can be made in 2 different versions.

MAC1 is the capsule made as a separate commercial product, which may be sold to a aerosol filler located far away from the capsule manufacturing facility.

MAC2 is the capsule, which needs to be charged by the gas directly at the aerosol can filling facility due to unbalanced state of the gas filling in the capsule in solid (ice) or liquid form.

For the aerosol can fillers both options may be of interest because the gas supply function and pressure supporting capability inside the final product (charged aerosol can), are practically the same for each. Each option has a number of specific advantages.

MAC1 has sealed plastic casing which must be equipped with inlet and outlet valves permitting the gas to go into the sorbent and to discharge the gas from the capsule when it is needed to support the pressure in the can. Before the dropping of MAC1 into the can the outlet valve is sealed by a soluble plug installed on the capsule before the gas charge through the inlet valve. In this option, the capsule may be stored without any losses of gas as long as practically necessary to deliver this separate unit to customer.

MAC2 has simple cheap plastic cover keeping both sorbent and gas inside. The capsule doesn’t require a tight sealing because immediately after charging the capsule with the gas in a solid or liquid form (time delay must be less than 10 min), the unit should be placed in the can before significant amount of gas escapes from the capsule. Only an elastic outlet valve (e.g. one-way valve) must be placed on any side of the capsule to prevent the penetration of the substance to be sprayed into the inner space of the capsule.

MAC1 and MAC2 shall occupy less than 10% of the package volume and the cost of each is limited to approx.  US$ 0.01 — 0.015 (10-15 mills). It means that taken into account the cost of substituted substances (alcohol, LPG and/or sponsored additives) the aerosol packages equipped by AEROPAC are cheaper and safer in all spectrum of aerosol applications!  Table of cost comparison of AEROPAC and VOC based aerosol, mills/unit

Material consumption, g	AEROPAC aerosol (MAC 2)	VOC based package (cost of substituted items)
Hydrocarbons,  75.0	—	38.0
Ethanol,   50.0	-	112.5
Water, 160.0	0.8	—
Capsule,  5.0	3.0	—
Carbon dioxide,  10.0 (purchased)	0.7	—  —
Activ. carbon,  9.0	9.0	—
Total	13.5   (14.8) COST SAVING = 137.0	150.5

Estimations have been made on the international price level

hydrocarbons (propane/isobuthane blend) - 500

ethanol  -  2250

water (deionized distillate)  5.0

carbon dioxide

self-made -  70

polymer for capsule (PE)  - 600

activated carbon  -  1000

Base of comparison: aerosol can with empty volume 330 ml, product content 250 ml (for VOC) and 285 ml (for AEROPAC),

product without propellant :

63 % more product to be sprayed with 13.65 cents per unit cost saving

Of course, MAC1 type of gas storage unit may be used  NOT ONLY IN AEROSOLapplications, but also in various market niches, e.g., to inflate rubber shells, toys, tires etc, to contain fuel gas

The technology is also suitable for onboard storage or distant fueling, gas saturation of any liquid and even for production of simple spraying devices for decoration or cleaning, etc.

Commercial potential of the AEROPAC capsules has been compared with the world aerosol market with an annual volume of approx. 8 billion units.

The technology is using by company VOCCO (ChimProm, Volgograd, Russia) for aerosol silicon lubricant and in small scale for food additives in Moscow company.

14.11.2006, 4561  просмотр.